The present invention relates, as novel industrial product, to a process for manufacturing an artificial leather composite material capable of replacing leather and endowed with excellent mechanical properties and fabricated, according to paper-making techniques, from a support comprising cellulosic fibres.
A large variety of products intended to imitate leather and manufactured by various techniques is known to exist at present. However, all these products are far from being perfect from the aesthetic point of view, and, in addition, they prove particularly difficult to manufacture.
To prepare these products, several technical solutions have been proposed for solving the problem of obtaining a material for replacing leather, (i.e. artificial or imitation leather).
According to one of these solutions, a cellulosic textile support (woven or non-woven) is impregnated and then coated on the surface, (by direct coating or by transfer), with resins (particularly cellulosic, acrylic, vinylic resins or resins of the polyurethane type) in solutions of inflammable and/or toxic solvents (particularly benzene, toluene, xylene, methylethylketone, dimethylformamide, tetrahydrofuran and ethyl acetate, etc . . . ). Unfortunately, such a technique requires the use of complicated installations which involve considerable operating costs with respect to the very strict rules of hygiene and safety.
To prepare the vinylic leathers which exist on the market, a technical solution which is relatively close to the preceding one is employed, which consists of using a resin of vinyl chloride polymers or copolymers, a large quantity of plasticizers (45 to 120% by weight of plasticizer, such as dioctylphthalate and butylbenzylphthalate, with respect to the weight of the resin), and solvents, acting as diluents, such as xylene.
Furthermore, according to French Pat. No. 1 397 666, another technical solution has been proposed which consists of treating a support surface composed at least in part of a mixture of rubber, with a grafted polymer (prepared from an acrylic monomer and a rubber) to form an intermediate layer, and then creating an aqueous suspension of a polymer to form the outer layer.
Another technical solution described in French Pat. No. 2 246 684 consists of applying on a support (textile, leather or split leather) a dispersion of polymers and vulcanisation agents, then applying heat for coagulating said dispersion.